Your mom is right. For plenty of energy, try to get as much sleep as your body requires. And remember that sleep before midnight is the most restful. Get plenty of moderate exercise, and steer clear of the junk food.
Schedule with friends a weekly activity that you will all find time to participate in during the school week. Play a game of Frisbee on the Freshman Quad, watch ER in the campus center, go to Flicks Sunday nights, or trek to town for a slice of Antonio's for example.
Avoid all-nighters. Break down your work into reasonable nightly chunks, and then sit down with your calendar and plan accordingly. Alert your roommates a few days in advance about your impending deadline so that they can be sure not to throw a party, etc on the night before your paper, midterm, etc is due.
Take a walk in the Bird Sanctuary (ask your RC how to get there) or visit Mead Art Museum.
Regress! Try finger painting again, play with playdough, or draw pictures with crayons to hang on your walls.
Treat yourself every once in a while. Play pool in the campus center, buy the latest issue of your favorite magazine, wake up ten minutes earlier than usual for an extra long shower.
If you are feeling especially overwhelmed, make a "To Do" list, listing the most urgent tasks first. Things look less daunting on paper than they do in your head, and the ranked list gives you a plan of attack.
Make things easier on yourself. Go see the Writing Counselor for help writing your paper, whether you need ideas to get you started or advice on editing.
Slow down the pace of your life. Answer the phone on the fifth ring instead of the first, sit outside your dorm room instead of rushing inside, enjoy Valentine for the company, if not for the food.
When you're confused about topics or class assignments, go see the professor. They all have office hours, and talking about how the class is going for you will ease your anxiety, as well as offer you a chance to get to know your professors.
Create a comfortable workspace. Put a pillow on your desk chair, decorate the walls with prints and pics of your family and friends, and make sure you have a good reading lamp.
Or, find a good place to study, if you are distracted in your room. Some Amherst favorites: the steps in front of the Campus Center (weather permitting), the Music Library in Buckley (bring a CD since many of the carrels have stereos with headphones!), the Bruss Room in Johnson Chapel, and the Media Center in Frost.
Take a nap. Maybe you haven't been getting enough good sleep.
Don't keep your stress inside. Vent with a friend, call home, or write in a journal. And you can always talk to your RC. If this doesn't help, make an appointment to see a counselor in the Counseling Center, 3rd floor Johnson Chapel at x.2354.